import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

num = 10 ** 6 + 1 #適当に値を入れる
L = [1 for i in range(num)]; L[0] = 0; L[1] = 0
plist = []
for i in range(num):
	if L[i] == 1:
		plist.append(i); c = 2
		while i * c <= num - 1:
			L[i * c] = 0; c += 1

#処理内容
def main():
	N = int(input())
	ans = 0
	for r in plist:
		if r ** 2 > N:
			break
		for p in plist:
			if p >= r ** 2:
				break
			if L[r ** 2 - p] == 1:
				# print(p, r**2-p, r, r**2)
				ans += 1

	print(ans)





if __name__ == '__main__':
	main()